1. Field of the Invention
This invention relates to a ball and socket type joint of the type used in vehicular steering and chassis applications, and more particularly toward such a ball socket assembly in which a pre-established compressive load is captured between the articulating components during an assembly operation.
2. Related Art
Ball and socket type assemblies are typically used in vehicular applications where three-dimensional movement of a wheel, and in particular a steerable wheel, is required when a vehicle is turning and/or the suspension is accommodating movement over rough terrain. In the normal course of operation, ball sockets are subjected to very high stresses. These stresses are transmitted through the stud of the ball socket assembly into an associated suspension member, which may be a steering knuckle, control arm, steering link, rack and pinion unit or other feature.
In particularly demanding applications, such as, for example, experienced by off-road vehicles and commercial vehicles, it is sometimes desirable to fabricate the components in a ball and socket assembly from metallic compositions. Thus, an “all metal” design can provide enhanced durability as compared with the prior art, light-duty structures which incorporate plastic and/or elastomeric pre-loaded articulating components.
During the manufacturing assembly operation, the ball stud of a ball and socket type assembly is loaded into a housing and captured between outer and inner bearing pieces to establish the articulating joint. A resilient spring-like member is typically placed into service between the housing and the articulating components to facilitate the pre-load compression setting. This resilient member may comprise a Belleville washer or similar type spring component or may comprise a polymeric elastomer for this purpose. Such prior art light-duty ball and socket assemblies which utilize plastic and/or elastomeric components are relatively forgiving in their assembly methods needed to achieve and maintain a preload compression setting, as compared with the heavy-duty all metal designs. Rather, the more durable all metal type ball and socket assemblies have proven to be extremely sensitive to the pre-load compression stresses established during the assembly operations. This sensitivity frustrates high through-put manufacturing as well as complicates a consistent quality achievement in mass production settings. Accordingly, there is a need for an improved method of controlling the pre-load clearance in a ball and socket assembly, and in particular within such assemblies of the “all metal” type.